Process for fulling textile fabrics



3,00,055 Patented Get. 31, 1961 3,006,055 PRQCESS FDR FULLiNG TEXTELE FAERI CS Robert Stuart Graph, Wilmington, Del assignor to E. I. du Pont de Nenionrs and Company, Wihnington, Del a corporation of Delaware No Drawing. Filed Feb. 21, 1953, Ser. No. 716,540 2 Ciaims. (Ql. 261) This invention relates to a fabric finishing process. More particularly it relates to a novel and useful process for fulling wool-containing fabrics.

It is an object of the present invention to provide a novel and useful process for fulling wool-containing fabrics to provide improved surface cover and continuity and improved flannel-like surface on fiat fabrics.

Another object is to provide novel and useful fulled fabrics containing minor amounts of Wool in the presence of major proportions of synthetic non-fullable staple fibers.

These and other ob'ects will be apparent in the course of the following specification and claims.

The fulling phenomenon, i.e., the displacement and intermingling of the fibers in a Woven or knitted fabric, has been known to be possible, using the traditional method, only when applied to a fabric containing at least about 60% by weight of wool fibers. The traditional fulling procedure has involved intermittent mechanical compression, as by beating or twisting, and shrinking under the influence of heat and moisture. At least partly due to the epithelial nature of the individual fiber, the intermittent stimuli cause the wool fiber in the yarn to creep toward its root end. This creeping results in a random wool fiber arrangement within the fabric which may hide the weave pattern.

In accordance with the present invention a process A worsted shetland type fabric with a 2 x 2 twill construction and having a weave count of 35 x 46 is woven from a yarn containing a stock blend of 40% of 3-denier, 3-inch length polyacrylonitrile staple, 20% of 3-denier, 3-inch length high shrinkage (by high shrinkage is meant fibers produced under conditions to give a residual shrinkage of or more in boiling water) polyacrylonitrile staple and 40% wool. The fiber is spun into a 2/24 worsted count yarn for warp and 1/22 worsted count yarn for filling. The warp singles have a Z twist of 8.5 turns per inch and are plied with an S twist of 7.1 turns per inch. The filling yarns have an S twist of 8.1 turns per inch. The greige is finished by the steps of 1 /2 hour soap fulling, washing in a dolly with water at 160 F. for 1 hour, drying on a pin tenter at 260 F., shearing and semidecating with 4 minutes steam and 2 minutes vacuum. At this point the fabric, although finished on regular textile equipment, is thready, has a hard handle and a lean, garish appearance.

A 4-yard sample of the above finished fabric (weighing approximately 1135 grams) is immersed at 130 F. in an aqueous soap solution containing 16% by weight of green soap (1680 grams water and 320 grams soap), in order to wet-out the fabric. It is then transferred to the loading drum (diameter of 27 inches) of a Prosperity tumble washer. The washer is run at 20 rpm. with its drain open and water supply valves closed. A steam feed is supplied to provide a temperature of 180 F. After tumble fulling relaxed for 45 minutes under these conditions, the fabric is tumble scoured at 200 F. for 20 minutes in 17 gallons of water.

The fabric is then dried at 260 F. on a pin tenter and semi-decated with 4-minutes steam and 2 minutes vacuum. The product is observed to be well fulled and to have an excellent appearance and handle. The additional average linear warp and weft-wise shrinkage is approximately 5% more as a result of the tumble fulling action, compared to a control fabric not so treated.

When a sample of the unfulled fabric in the greige is tumble fulled at F. for 4 hour under the conditions outlined for tumble fulling above, followed by a tumble scour at 195 F. for /4 hour, it is observed to be overfulled.

A sample of fabric similar to the above-described fabric but Woven from a yarn containing a stock blend of 60% of 3-denier, 3-inch length low shrinkage (i.e., about 3% residual shrinkage) polyacrylonitrile staple and 40% wool is tumble fulled at a temperature of F. for /2 hour and at 175 F. for /2 hour, plus a tumble scour at 180 F. for hour. The sample is observed to be of satisfactory appearance despite under-fulling. The handle is lean.

EXAMPLE II A worsted type fabric with a 2 x 2 twill construction and having a weave count of 36 x 34 is woven from a yarn containing a stock blend of 20% of 4.5 denier, 2%-inch, 20% of 3-denier, 2 /z-inch, polyethylene terephthalate staple, 20% of 3-denier, ZVz-inch high shrinkage (by high shrinkage is meant fibers produced under conditions to give a residual shrinkage of 10% or more in boiling water) polyethylene terephthalate staple, and 40% wool. The fiber is spun into a 17/ 2 cotton count warp yarn and 18.5/2 cotton count filling yarn. Both singles have a Z twist of 12 turns per inch and are plied with an S twist of 11 turns per inch.

A 10-yard sample of this fabric is wet-out with the soap solution as described in Example I and placed in one compartment of a commercial tumble machine. The compartment is a cylinder about 3.5 feet long and is a /3 section (120) of a circle (3.5 feet diameter) in cross section. The fabric is tumble fulled relaxed at a temperature regulated between and F. for 1 hour. It is thereafter tumble scoured for 1 hour at F. and for an additional 5 minutes at 210 F. The product has a felt-like handle and appearance. It is considerably over-fulled.

Another sample of the same fabric as employed above is fulled for 1 hour at 100 F. on a standard fulling mill. It is thereafter beck scoured at 170 F. for of an hour plus an additional 1 minute at 200 F. The temperature is thereafter decreased slowly over a period of about 15 minutes to 160 F. The pattern of the fabric sample is clear and garish. The fabric is lean and without cover.

EXAMPLE III A fabric of similar construction to that described in Example II is made wherein the yarn is produced from a stock blend of 60% polyethylene teraphthalate staple, 20% high shrinkage polyethylene terephthala'te staple, and 20% wool. The tumble fulling of a sample of this fabric following the procedure described in Example II produces an over-fulled fabric. When the sample is subjected to the standard fulling mill and subsequent scour as described in Example II, no evidence of fulling is apparent.

EXAMPLE IV A fabric is produced having a construction of the fabric described in Example II but woven from a yarn containing a stock blend of 40% polyacrylonitrile staple, 20% polyethylene terephthalate staple, 20% high shrinkage polyethylene terephthalate staple, and 20% wool. Overfulling results when a sample of this fabric is subjected to the tumble fulling conditions of Example II. No fulling is apparent when a sample of this fabric is subjected to the regular fulling mill procedure as outlined in Example II.

While the optimum conditions for the tumble fulling operation will depend upon fabric and yarn structure and composition to some extent, fabrics containing even as little as wool may be fulled in accordance with the process of the present invention. Fabrics containing less than about 10% wool undergo no appreciable fulling or fiber migration in this process. Thus, the fabric may be woven or knitted. Also, the process may be applied to non-Woven fabrics to improve their aesthetic properties. A tightly woven fabric will require more drastic conditions, i.e., higher temperatures, longer periods of tumbling, more concentrated fulling agent solutions, and the like, than will a more loosely woven fabric. The process, therefore, is of particular value when applied to fabrics loosely woven from spun yarns containing wool/ synthetic fiber blends wherein the wool fiber component comprises 10%-40% and the synthetic staple fiber comprises 60%- 90% by weight. Such fabrics are not amenable to fulling by the standard fulling techniques of the art. As is illustrated in the example, tumble fulling of the greige fabric may be accomplished by less drastic conditions than is possible in the fulling of the finished fabric. Where the fabric has been dyed, care must be taken not to employ a fulling agent which will adversely affect the dye and to avoid temperatures at which the dye will be removed. The twist of the yarn is another factor which along with the looseness or tightness of the weave will control the conditions of the operation. Many different fabric types may be treated by the process of this invention, including worsted shetland, worsted flannel, woolen flannel, cheviot, sport shirtings, and the like.

Prior to tumbling, the fabric is wet-out with water. For faster and more complete fulling the water preferably contains a fulling aid (i.e., a fulling agent). By a fulling agent is meant one which accelerates wool fiber migration during fulling. Specific examples of such materials include oleate soap, or green soap, or acetic acid with a synthetic detergent, or soda ash with a synthetic detergent. The use of a detergent or Wetting agent alone will not cause fulling of the wool in the process of this invention. In addition to aqueous solutions these agents may be applied from other solvents which wet and swell the wool. The solutions may be applied by immersion of the fabric or by spraying or pad ding the fabric. It is sometimes advantageous to spray a mist of the solution containing fulling agent into the revolving tumbling barrel. In general, optimum concentration of fulling aid in its solution will vary with the nature of the particular aid employed and with the nature of the fabric treated. Generally, a concentration from about 3% to about 25% by weight is satisfactory. Pulling will proceed, however, without the presence of any fulling agent whatever. However, under such circumstances the period of tumbling must be increased.

Regardless of how much water or aqueous medium is used to wet-out the fabric prior to tumbling, the tumbling action should be applied to fabric which is merely dampened with water. A safe operating limit is to employ no more than about three times as much water as fabric being tumbled on a weight basis. That is, any excess water is drained off the fabric, leaving the fabric just wet before actual tumbling begins. The tumbling period will depend upon the temperature employed, the type of fabric, the nature of the fulling aid, and the like. F or most conventional fabrics, a period of about 30 minutes at a temperature of about 150 F. is satisfactory, where the drum revolves at a rate of about rpm. Temperatures as low as F. are often satisfactory, and as high as 200 F. provided the fibers or dyes therein are not damaged by the higher temperatures. Generally, however, higher temperatures permit shorter tumbling periods. With some fabrics a period of only 15 minutes of tumble fulling is sufiicient to cause wool fiber migration into adjacent yarns.

Following the fulling operation, it is convenient to scour the fabric in the same apparatus employed for fulling, using a large excess of water. For example, sixty times as much water is used to scour the fabric in Example I compared with one to three times as much water to tumble full the fabric. The purpose of this step is to remove fulling aid and relax fibers in the fabric. Generally, a tumble scour at a temperature of about F. for a period of A: hour is satisfactory. However, these conditions must be varied to attain optimum results with any particular fabric employed.

The nature of the tumble fulling apparatus employed is not critical. It is essential only that a revolving drum with internal baffles or projections which rotates on its axis to be provided which permits drainage of excess fulling aid solution and is also equipped to permit heating during rotation. This unit may vary relative to the diameter of the drum from about 4 feet as used in a commercial laundry to about 20 inches as used in a home washer. In general, for a drum of about 42 inches in diameter a speed between about 15 r.p.m. and 30 rpm. is recommended.

As taught in the examples, it is preferred that the fabric be plaited with its edges tacked through the selvedges prior to loading in the drum. This procedure has been found to prevent tangling of large pieces and more important the fabric is then in a bundle which is carried by baffies toward the top of the cylinder and dropped to the bottom. This provides the heating or working action essential for fulling in this process. In addition, the tumbling action must be applied to the fabric while it is completely relaxed in order to achieve the fulling desired in accordance with this invention.

After the tumble fulling and scouring operations, the fabric is usually rinsed and dried on a pin tenter drier.

It will be noted from the above that the presence of a high shrinkage synthetic fiber assists in the fulling operation. While applicant does not wish to be bound by any theory of operation, it is felt that this is due to shrinkage assistance offered by the high shrinkage fibers. It is not essential that high shrinkage fibers be present. By high shrinkage fiber is meant a fiber which has been produced under conditions to give 10% or more residual shrinkage in boiling water.

Additional representative fabrics composed of mixtures of various synthetic non-fullable fibers with wool and which are useful in the fulling process of this invention are described in Table 1 below, all of which samples are fabrics woven from spun yarns with a 2 x 2 twill construction. The acrylic fibers referred to in the table are polyacrylonitrile staple fibers, and the polyester fibers used are polyethylene terephthalate staple fibers. Other synthetic non-fullable fibers which may be used include those made from polyamides, cellulose acetate, and copolymers of vinyl chloride and vinylidene chloride. All of the fabrics tumble fulled in Table I possess noticeably better surface cover and appearance than the corresponding control fabrics which received no tumble fulling treatment. Table II shows another typical fabric woven from spun yarns which has been tumble fulled in accordance with this invention so that the wool fiber migration into adjacent yarns is noticeable and a pleasing appearance is visible in the finished fabric. In comparison a control fabric of the same construction shows no fullin-g whatsoever after treatment in a conventional fulling mill (i.e., rotary type) in which there is no tumbling action on the fabric.

Table I Weave Twist in Twist Tumble Tumble Fulling Ex. No. Count Yarn Composition Plys Singles in Period, Temp, Agent Plys hrS. F.

36x 48 60/40 acrylic/wool Ti 3 3 1 Green Soap 32 x 30 60/40 acrylic/wool.. 11 1 115 Do. 36 x 30 80/20 polyester/wool. 12 11 1 115 D0. 36 x 30 60/40 polyester/wool. 12 11 1 115 Do. 36 X 34 60/20/20 polyester/rayon/wool. 12 11 2 120 Do. 36 x 34 60/30/10 polyester/zein/wool 12 11 2 120 D0. XI. 35 x 46 60/40 acrylic/wool f 3g- XII 36 x 34 40/40/20 acrylic/polyester/wool. 12 11 1 165 Do. XIII. 26 x 70/30 acrylic/wool 6.7/1 cc s 9 33:

Table II Weave Twist in Twist Fulling Fulling Ex. No. Count Yarn Composition Plys Singles Piln Fulling Period T eig p Agent XIV 36 X 60/40 po1yester/wo01 18/2 cc... 12 11 Tlilfibhle Fulled 115 Green Soap.

rs. Control 36 x 30 60/40 polyester/wool..-" 18/2 cc... 12 11 Rotary Fulled 100 Do,

The tumble fulling operation can be combined with other types of fabric processes involving liquid treatment For instance, the tumble fulling may be preceded as well as followed by a scour. Desizing operations may be carried out in the tumbling apparatus. Likewise, the same apparatus is suitable for dyeing either before or after the tumble fulling operation.

In addition to the fulling and wool fiber migration obtained from the present invention, there are several other advantages realized in this process. The fabrics after treatment by the present invention are flat fabrics that show increased surface cover as well as bottom cover, increased surface continuity (i.e., decreased threadiness), no change in slickness, and constant or decreased resilience. By the present process, almost all available residual lengthwise shrinkage in the fiber components may be realized.

Many equivalent modifications will be apparent to those skilled in the art from a reading of the above without a departure from the inventive concept.

I claim:

1. A process for fulling a fabric produced from yarn containing from 10% to 40% by weight Wool, the remainder of the fiber in the said yarn being synthetic, which comprises wetting out the said fabric with an aqueous medium containing 3% to 25% by weight of the said medium of a fulling aid, draining excess liquid from the said fabric until no more of the said liquid than about three times the weight of the said fabric remains on the said fabric and thereafter subjecting the said wet-out fabric to relaxed tumbling at a temperature between F. and 200 F. for a period of at least 15 minutes to attain wool fiber migration into adjacent and crossing yarns.

2. The process of claim 1 wherein the said synthetic fiber in the fabric to which the process is applied has a residual shrinkage of at least 10%.

References Cited in the file of this patent UNITED STATES PATENTS 1,952,407 Beaty Mar. 27, 1934 2,125,925 Jones Aug. 9, 1938 2,407,602 Clu-ley et al. Sept. 10, 1946 2,423,828 Chaghon July 15, 1947 2,586,106 Speakman et al. Feb. 19, 1952 2,669,002 Dalton et al. Feb. 16, 1954 FOREIGN PATENTS 575,072 Great Britain Feb. 1, 1946 

1. A PROCESS FOR FULLING A FABRIC PRODUCED FROM YARN CONTAINING FROM 10% TO 40% BY WEIGHT WOOL, THE REMAINDER OF THE FIBER IN THE SAID YARN BEING SYNTHETIC, WHICH COMPRISES WETTING OUT THE SAID FABRIC WITH AN AQUEOUS MEDIUM CONTAINING 3% TO 25% BY WEIGHT OF THE SAID MEDIUM OF A FULLING AID, DRAINING EXCESS LIQUID FROM THE SAID FABRIC UNTIL NO MORE OF THE SAID LIQUID THAN ABOUT THREE TIMES THE WEIGHT OF THE SAID FABRIC REMAINS ON THE SAID FABRIC AND THEREAFTER SUBJECTING THE SAID WET-OUT FABRIC TO RELAXED TUMBLING AT A TEMPERATURE BETWEEN 100*F. AND 200*F. FOR A PERIOD OF AT LEAST 15 MINUTES TO ATTAIN WOOL FIBER MIGRATION INTO ADJACENT AND CROSSING YARNS. 